Conveyor chain for mining machinery

ABSTRACT

A chain for a conveyor comprising an elongated base means ( 8, 9 ) having a bottom and upstanding side guides or flanges ( 11, 12 ) is provided. The chain is a continuous chain adapted to be driven so that one of its spans moves longitudinally along the upper surface of the base means bottom ( 10 ) and between side guides or flanges in a conveying direction so as to advance the material being conveyed. The chain comprises a plurality of Y-shaped connector links ( 20 ) and a plurality of flight arms connecting links ( 34 ) having arms attached thereto and normally extending substantially transversely of the conveying direction. Adjacent elements ( 41 ) are joined together by a series of bearing and retaining pins ( 30, 31 ) so as to permit vertical and horizontal articulation. The flight arms are attached to the flight arm connecting links ( 34 ) independently of the main bearing pins ( 30 ) that hold the various links of the chain together.

TECHNICAL FIELD

The present invention relates generally to conveyor chains, and, moreparticularly to mining machinery conveyor chain link bodies withattachments for flight arms.

BACKGROUND OF THE INVENTION

While conveyors with which the chain of the present invention areintended to be used may have many applications, for purposes of anexemplary showing, such conveyors will be described with respect totheir use in the mining industry, although their use is not intended tobe so limited.

Pusher-type chain conveyors, as used in the mining industry, are foundboth in the form of separate conveying units, and as integral parts ofcontinuous mining machines. A typical continuous mining machine, forexample, is self-propelled and is provided at its forward end withcutting means shiftable in such a way that an entry is cut in thematerial being mined. The entry is so sized as to permit the passage ofthe mining machine therethrough. Since the cutting operation is acontinuous one, it is necessary to provide means to move the cutmaterial from in front of the mining machine and to convey it out of theentry. To this end, the mining machine usually incorporates one orseveral conveyors in its construction, the conveyors acting successivelyto transport the cut material rearwardly of the machine. Frequently, themining machine further incorporates a “tail conveyor” which is a part ofthe mining machine, located at its rearward end. The purpose of the tailconveyor is to deliver the cut material to other conveying means bywhich it is removed from the entry. The other conveying means maycomprise mine cars, portable belt conveyors, or the like.

The most frequently encountered form of tail conveyor, in associationwith a continuous mining machine, comprises a section of conveyor basemeans mounted on the mining machine body. One or more additionalsections of conveyor base means are connected thereto end-to-end, andextend beyond the rearward end of the mining machine body. All of thebase means sections are characterized by a bottom portion provided withlongitudinally extending, upstanding side guides or flanges. In orderfor the tail conveyor to perform its task properly, the various sectionsthereof must be capable of both lateral and vertical movement withrespect to each other. This enables the cut material to be delivered toa desired point despite changes of position of the mining machine as itadvances in the entry and changes in level of the entry floor.Similarly, this lateral and vertical movement capability of the conveyorsections enables the shifting of the desired delivery point for thematerial being mined, as required.

The tail conveyor typically incorporates a continuous pusher-typeconveyor chain which is driven along the length of the conveyor basesections. The chain is normally provided with a plurality of rigidpusher elements, normally extending substantially transversely of theconveying direction. The pusher elements are located at spaced intervalsalong the chain. Adjacent pusher elements are joined together by aseries of alternate block-like links and plate-like links. At one end ofthe machine's conveyor, the continuous chain passes over a drivensprocket. At the other end of the conveyor, the chain passes over adriven or idler sprocket, or roller.

Typically in the underground mining industry, machine downtime is veryexpensive. Should a conveyor chain fail (due to sudden impact or wear),the chain often would come apart during production causing several hoursof expensive and unproductive downtime while the chain was repaired.Most often a conveyor chain fails from impact loads on the flight arms.These impacts over time cause a fracture which then causes the welded-inpins to fail.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrates several aspects of the present invention, andtogether with the description and claims serves to explain theprinciples of the invention. In the accompanying drawings:

FIG. 1 is a semi-diagramatic plan view of a typical continuous miningmachine having a tail conveyor utilizing a pusher-type conveyor chain;

FIG. 2 is a top plan view of one embodiment of the preferred chainconnector link of the present invention;

FIG. 3 is a side elevational view of the connector link of FIG. 2;

FIG. 4 is a top plan view of one embodiment of the flight arm chainconnector link of the present invention;

FIG. 5 is a side elevational view of the flight arm chain connector linkof FIG. 4;

FIG. 6 is an end view of the flight arm chain connector link of FIG. 4;

FIG. 7 is a top plan view of another embodiment of the flight arm chainconnector link of the present invention;

FIG. 8 is a side elevational view of the flight arm chain connector linkof FIG. 7;

FIG. 9 is an end view of the flight arm chain connector link of FIG. 7;

FIG. 10 is a top plan view of one embodiment of the flight arm of thepresent invention;

FIG. 11 is a side elevational view of the flight arm of FIG. 10;

FIG. 12 is an end view of the flight arm of FIG. 10;

FIG. 13 is a top plan view of another embodiment of the flight arm ofthe present invention;

FIG. 14 is a side elevational view of the flight arm of FIG. 13;

FIG. 15 is an end view of the flight arm of FIG. 13;

FIG. 16 is a perspective view of a segment of one embodiment of theimproved conveyor chain of the present invention;

FIG. 17 is a top plan view of a segment of the improved conveyor chainof the present invention shown in a curved configuration;

FIG. 18 is a perspective view of a segment of the improved conveyorchain of the present invention using both preferred embodiments offlight arm connector links and flight arms; and

FIG. 19 is a side view of the preferred elongated sprocket of thepresent invention showing a segment of the improved conveyor chain ofthe present invention being driven thereon.

DETAILED DESCRIPTION OF THE INVENTION

For a better understanding of the invention, reference is first made toFIG. 1, illustrating an exemplary environment for the chains of thepresent invention. FIG. 1 diagrammatically illustrates a typicalcontinuous mining machine generally indicated at 2 and provided with atail conveyor, generally indicated at 3. The mining machine has a bodyportion 4 which is usually mounted on wheels or treads and isself-propelled. At the forward end of the mining machine, cutting meansare provided as shown at 5 and 6. These cutting means 5 and 6 may takevarious well known forms and are mounted on means such as the frame 7,enabling the cutting means to be shifted in such a way that they willcut an entry large enough to receive and to permit advancement of themining machine 2 in the cutting direction indicated by arrow A.

By various well known conveying means, the cut material at the forwardend of the mining machine is gathered and transported over or throughthe mining machine to the tail conveyor 3. This last mentioned conveyorcomprises a conveyor base means, illustrated in FIG. 1 as made up of twosections 8 and 9. The base means section 8 has a bottom portion 10 andupstanding side guide or flanges 11 and 12. Similarly, the section 9 hasa bottom portion 13 and upstanding side guides or flanges 14 and 15. Thesection 9 is mounted on a boom 16 articulated to the rearward end of themining machine body 4 as at 17. The articulation is such that the boom16 and its conveyor base means section 9 are shiftable with respect tothe conveyor base means section 8 both in the vertical plane and thehorizontal plane for reasons explained above. A pusher-type conveyorchain, generally indicated at 18, extends along the length of theconveyor base means sections 8 and 9 and is adapted to be driven alongthe upper surface of their bottom portions 10 and 13. It will beunderstood that the chain 18 is a continuous chain. Normally it will bedriven by a sprocket at at least one end of the tail conveyor 3.

As shown in FIG. 1, a typical chain 18 is provided with a plurality ofspaced pusher elements 19, extending substantially transversely of theconveying direction indicated by arrow B. It will be seen that thepusher elements preferably extend to both sides of the chain 18 and thatthe pusher elements are located at predetermined intervals along thelength of the chain.

To assure a thorough understanding of the chains of the presentinvention, the individual parts used to make up the chains will be nextdescribed in detail. Reference is first made to FIGS. 2, 3 and 4 inwhich an exemplary chain connector link of the present invention isgenerally indicated at 20. In all of the figures, like parts have beengiven like index numerals.

As best shown in FIGS. 2 and 3, the improved conveyor chain of thepresent invention includes a plurality of generally “Y-shaped” chainconnector links 20. Each chain connector link 20 preferably includes apair of spaced forwardly extending arms 21 and a single rearwardlyextending arm 22. A space 23 is provided between each pair of forwardlyextending arms 21 that is adapted to receive a rearwardly extending arm22 of an adjacent chain connector link 20. Preferably, as shown in FIG.2, space 23 is partially defined by a portion 24 of the chain connectorlink 20 of substantially semi-circular or arcuate cross section. Morepreferably, each forwardly extending arm 21 includes a chamfered orrounded inner edge 25.

According to an important aspect of the present invention, eachrearwardly extending arm 22 includes an elongated hole 26 disposedtransversely therethrough. Preferably, as shown in FIGS. 2 and 3, theelongated hole 26 is preferably of oblong or elliptical cross-section.More preferably, the elongated hole 26 includes a center portion 27 of alesser diameter than either end portion 28 of the elongated hole.

Each forwardly extending arm 21 includes a transverse opening 29 that isaligned with the transverse opening 29 on the corresponding forward arm21. Preferably, the transverse openings 29 of the forward arms 21 aresubstantially of circular cross section. As best shown in FIG. 16, andin order to secure a pair of adjacent chain connector links 20 together,a bearing pin 30 is inserted through the transverse openings of theforward arms of one chain link body and through the rearwardly extendingarm of another chain link body. The bearing pin is preferably held inplace by one or more retaining pins 31 inserted in correspondingretaining pin holes 32 disposed in the forward arms 21 and the bearingpins 30.

As can best be seen in FIG. 2, each forwardly extending arm is at leastpartially of substantially elliptical cross section. Preferably, thedistal end of the rearwardly extending arm includes a rounded end 33.

As best shown in FIGS. 4-6, the improved conveyor chain of the presentinvention includes a plurality of flight arm connector links 34. Eachflight arm connector link 34, similar to each chain connector link 20,preferably includes a pair of spaced forwardly extending arms 21 and asingle rearwardly extending arm 22. A space 23 is provided between eachpair of forwardly extending arms 21 that is adapted to receive arearwardly extending arm 22 of an adjacent flight arm chain connectorlink 34. Preferably, as shown in FIG. 4, space 23 is partially definedby a portion 24 of the flight arm chain connector link 34 ofsubstantially semi-circular or arcuate cross section. More preferably,each forwardly extending arm 21 includes a chamfered or rounded inneredge 25.

Similar to the elongated holes 26 of the chain connector links 20, eachrearwardly extending arm 22 of the flight arm connector links 34 alsoincludes an elongated hole 26 disposed transversely therethrough.Preferably, as described previously, the elongated hole 26 is preferablyof oblong or elliptical cross-section. More preferably, the elongatedhole 26 includes a center portion 27 of a lesser diameter than eitherend portion 28 of the elongated hole. Optionally, and as shown in FIGS.4 and 6, the elongated hole 26 may be substantially of circularcross-section.

Preferably, and as described previously, each forwardly extending arm 21includes a transverse opening 29 that is aligned with the transverseopening 29 on the corresponding forward arm 21. Preferably, thetransverse openings 29 of the forward arms 21 are substantially ofcircular cross section. As best shown in FIG. 16, and in order to securea flight arm connector link 34 with an adjacent chain connector link 20together, a bearing pin 30 is inserted through the transverse openingsof the forward arms of one chain link body 20 and through the rearwardlyextending arm of another chain link body 20 or flight arm connectinglink 34. The bearing pin is preferably held in place by one or moreretaining pins 31 inserted in corresponding retaining pin holes 32disposed in the forward arms 21 and the bearing pins 30.

As best shown in FIGS. 4 and 5, each flight arm connector link 34includes a pair of laterally extending flight arm attachment projections35 adapted to receive a corresponding flight arm. Preferably, eachlaterally extending flight arm attachment projection 35 includes atleast one, and preferably a pair of, flight arm securing holes 36.Preferably, the each securing hole 36 extends from a front face 37 ofthe flight arm attachment projection 35 to a rear face 38 thereof. Ascan be seen in FIG. 6, the widths of each flight arm attachmentprojection 35 is substantially identical to that of adjacent arms 21 and22.

In an alternate embodiment of the flight arm connecting link 34 a, andas best shown in FIGS. 7-9, the flight arm securing holes are disposedfrom a top surface 39 of a flight arm attachment projection 35throughwardly to a bottom surface 40 thereof. In this embodiment, and asshown in FIG. 9, the flight arm attachment projections 35 are of a widthless than adjacent arms 21 and 22.

Reference is made to FIGS. 10-12 wherein one embodiment of a flight arm41 is shown. Preferably each flight arm includes an elongated body 42having a flat, planar bottom surface 43. The body 42 has a central ribor web 44 acting as a pusher for the material being conveyed. The outerfree end of the flight arm 41 is provided with a knob-like portion 45which can ride against side guide elements 11, 12, 14 and 15 associatedwith conveyor sections 8 and 9. A chain link connecting portion 46 isprovided with a recess 47 to facilitate attachment to a correspondingflight arm attachment projection 35 of a flight arm connecting link 34.The chain link connecting portion is provided with opposing prongs 48having bearing holes 49 disposed therethrough. Bearing holes 49 areadapted to match up with corresponding flight arm securing holes 36 of acorresponding flight arm attachment projection 35 of a flight armconnector link 34. Bearing pins may be inserted through holes 36 and 49to attach components 34 and 41 together. Bearing pins may be held inplace by retaining pins disposed though retaining pin holes 51 and 32 ofthe flight arm 41 and flight arm connecting link 34 respectively. Theembodiment of the flight arm 41 shown in FIGS. 10-12 is particularlyadapted for use with the embodiment of the flight arm connecting link 34of FIGS. 10-12.

Various other methods of flight arm attachments to the flight armattachment link 34 are possible other than the bearing and retaining pinassemblies described. For example, the flight arm may be doweled,bolted, keyed or interlocked to a corresponding link various ways asknown in the art. One advantageous feature of the above describeddesigns of the present invention is the separation of the flight armsfrom the main bearing pin 30. The separation of the flight arms 41 fromthe main bearing pins 30, allows for better quality steels to be usedwithout compromising the main bearing pins 30 toughness and fractureresistance in order to have good weldability (a requirement of prior artdesigns).

It should be appreciated that the various components may be comprised ofessentially any suitable material known in the art that exhibits therequisite strength and durability characteristics. The variouscomponents are preferably steel and may be forged or are more preferablycast. Preferably the flight arms are comprised of spring steel. In orderto reduce noise levels further during operation, composite steel andplastic or urethane components may be used.

A similar flight arm embodiment 41A with differently oriented bearingholes 49 and opposing prongs 48 is shown in FIGS. 13-15. Flight arm 41Ais adapted for use with and connection to the embodiment 34A of theflight arm connecting link shown in FIGS. 7-9.

As can be seen in the FIGS. 16-18, the complete chain will be comprisedof both “Y-shaped” chain connector links 20 and flight arm attachmentlinks 34 or 34A with flight attachments 41 or 41A fixedly disposedthereon. Preferably each elongated hole 26 is adapted to “loosely”receive the bearing pin 30 so as to permit articulation and to allow, asa result, the conveyor chain of the present invention to navigate curves(See FIG. 17). It should be appreciated that the chain has the abilityto negotiate curved conveyor sections by articulating via the elongatedhole 26 through which the bearing pin 30 has freedom to “rotate” aboutthe chain center and allow the chain the flexibility it needs to travelthrough the curved section. This offers a distinct advantage over knownprior art chains which incorporate welded-in main bearing pins. The mainbearing pin 30 preferably has an interference fit or may have a slightrotating fit in the transverse openings 29 of the forward arms 21 of thechain connector links 20. Depending upon its orientation in use, thelinks 20, 34, and 34A will preferably ride along the upper surfaces ofthe bottom portions 10 and 13 of conveyor sections 8 and 9 either on itssurfaces 30 and 31 or its surfaces 33 and 34.

As can be seen in FIG. 19, the improved chain of the present inventionis preferably driven by a six tooth dual sprocket 52. The chain ispreferably designed with an offset in pitch from forward to reverse toallow for the chain to be seated in a corresponding sprocket root 53.Advantageously, this configuration allows for the chain to remainengaged longer on the sprocket and to be conveyed directly onto aloading deck. This configuration serves to minimize interference withloading devices and improves both sprocket and chain life. The dual sixtooth sprocket also reduces the chains “striking energy” advantageouslyreducing chain drive noise.

The foregoing description of a preferred embodiment of the invention hasbeen presented for the purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseform disclosed. Obvious modifications or variations are possible inlight of the above teachings. The embodiment was chosen and described inorder to best illustrate the principles of the invention and itspractical application to thereby enable one of ordinary skill in the artto best utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

1. A conveyor chain comprising: a plurality of chain links connectedtogether in a chain, the chain links each including a pair of forwardarms extending in a forward direction on both sides of the link andhaving a space therebetween and a rearward arm extending in a rearwarddirection; the forward arms of one link configured to receive therearward arm of an adjacent link in the space between the forward arms,the rearward arm of the adjacent link configured to couple with theforward arms of the one link and form a continuous chain; the rearwardarm of each link extending a distance from the forward arms so that whenadjacent links are coupled together, an engagement space is createdbetween the forward arms of the one link and the forward arms of theadjacent link on both sides of the links; the engagement spacesconfigured to receive portions of sprockets that would engage theforward arms of the link on both sides of the chain for driving thechain.
 2. The conveyor chain of claim 1 further comprising: a flight armlink, the flight arm link including a pair of spaced apart forward armsextending in a forward direction on both side of the link and a rearwardarm extending in a rearward direction; the forward arms and rearward armof the flight arm link configured to couple with a respective rearwardarm and respective forward arms of adjacent links and form a continuouschain; an attachment projection positioned on the flight arm link; aflight arm configured for engaging the attachment projection to securethe flight arm to the flight arm link.
 3. The conveyor chain of claim 2wherein the attachment projection is positioned between where the frontand rear arms of the flight arm link couple with adjacent links.
 4. Theconveyor chain of claim 1 wherein the forward arms of a link includetransverse openings and the rearward arm of the link includes anelongated hole, the transverse openings of one link aligning with theelongated hole of an adjacent link to couple the links together.
 5. Theconveyor chain of claim 4 further including a bearing pin extendingthrough the aligned transverse openings and elongated hole in order tocouple the links together.
 6. The conveyor chain of claim 5 wherein theelongated hole has an oblong cross-section so that it receives thebearing pin loosely in the rearward arm and allows articulation of theone link with respect to the adjacent link.
 7. The conveyor chain ofclaim 4 wherein the elongated hole includes a center portion and an endportion, the center portion having a smaller dimension than the endportion.
 8. The conveyor chain of claim 1 wherein the forward armsinclude rounded edges proximate the space therebetween.
 9. The conveyorchain of claim 1 wherein a chain link includes an arcuate portion thatdefines the space between the forward arms.
 10. The conveyor chain ofclaim 2 wherein the flight arm attachment projection includes securingholes and the flight arm includes bearing holes, the securing holes andbearing holes being aligned when the flight arm engages the attachmentprojection.
 11. A conveyor system comprising: A conveyor chain includinga plurality of chain links connected together in a chain, the chainlinks each including a pair of forward arms extending in a forwarddirection on both sides of the link and having a space therebetween anda rearward arm extending in a rearward direction; the forward arms ofone link configured to receive the rearward arm of an adjacent link inthe space between the forward arms, the rearward arm of the adjacentlink configured to couple with the forward arms of the one link and forma continuous chain; the rearward arm of each link extending a distancefrom the forward arms so that when adjacent links are coupled together,an engagement space is created between the forward arms of the one linkand the forward arms of the adjacent link on both sides of the links;and a drive device, the drive device including at least two sprocketswith teeth, with one sprocket engaging the forward arms of the links onone side of the chain and another sprocket engaging the forward arms ofthe links on another side of the chain in respective engagement spacesso that the teeth of each sprocket engage the forward arms of the linksto drive the chain.
 12. The conveyor system of claim 11 wherein theforward arms of a link include transverse openings and the rearward armof the link includes an elongated hole, the transverse openings of onelink aligning with the elongated hole of an adjacent link to couple thelinks together.
 13. The conveyor system of claim 12 further including abearing pin extending through the aligned transverse openings andelongated hole in order to couple the links together.
 14. The conveyorsystem of claim 13 wherein the elongated hole has an oblongcross-section so that it receives the bearing pin loosely in therearward arm and allows articulation of the one link with respect to theadjacent link.
 15. The conveyor system of claim 13 wherein the elongatedhole includes a center portion and an end portion, the center portionhaving a smaller dimension than the end portion.
 16. A conveyor chaincomprising: a plurality of chain link assemblies connected together in achain, the chain link assemblies each coupled together so as to allowarticulation between adjacent link assemblies so that the chain cantravel in a curved path; each of the link assemblies using a pin forcoupling the link assembly with an adjacent link assembly forarticulation, with each link assembly having a freedom to rotate about achain center; the pins of the link assemblies extending laterally beyondthe chain center on either side of the chain center; a sprocketengagement area formed on each side of the center of the chain proximateto where the pins laterally extend, the sprocket engagement areaconfigured to receive part of a sprocket; at least one flight arm linkassembly in the plurality of link assemblies, the flight arm linkassembly using a pin for coupling the flight arm link assembly with anadjacent link assembly; a separate flight arm coupled to extendlaterally from the flight arm link assembly, the flight arm having aconnecting portion for connecting to the flight arm link assembly; theseparate flight arm coupled with the flight arm link assembly so thatthe connecting portion is maintained at a position that is laterallyspaced from the chain center outside of the sprocket engagement areas ofthe link assemblies.
 17. The conveyor chain of claim 16 furtherincluding a pair of separate flight arms with respective connectingportions, the separate flight arms each coupled with the flight arm linkassembly so that the respective connecting portions are maintained atpositions that are laterally spaced outside of where the sprocketsengage the link assemblies.
 18. The conveyor chain of claim 16 whereinthe flight arm connecting portion includes a recess to couple the flightarm to extend laterally from the flight arm link assembly.
 19. Theconveyor chain of claim 18 wherein the flight arm connecting portionrecess is configured to receive a portion of the flight arm linkassembly therein to couple the flight arm to extend laterally from theflight arm link assembly.
 20. The conveyor chain of claim 19 wherein theportion of the flight arm link assembly received by the connectingportion recess is an attachment projection spaced from the pins of thelink assembly.
 21. The conveyor chain of claim 18 wherein adjacent linkassemblies share a common pin for coupling with each other.
 22. Aconveyor system comprising: a conveyor chain including a plurality ofchain link assemblies connected together in a chain, the chain linkassemblies each coupled together so as to allow articulation betweenadjacent link assemblies so that the chain can travel in a curved path;each of the link assemblies using a pin for coupling the link assemblywith an adjacent link assembly for articulation, with each link assemblyhaving a freedom to rotate about a chain center; the pins of each linkassemblies extending laterally beyond the chain center on either side ofthe chain center; a sprocket engagement area formed in the linkassemblies on each side of the center of the chain proximate to wherethe pins laterally extend, the sprocket engagement area configured toreceive part of a sprocket; at least one flight arm link assembly in theplurality of link assemblies, the flight arm link assembly using a pinfor coupling the flight arm link assembly with an adjacent linkassembly; a separate flight arm coupled to extend laterally from theflight arm link assembly, the flight arm having a connecting portion forconnecting to the flight arm link assembly; the separate flight armcoupled with the flight arm link assembly so that the connecting portionis maintained at a position that is laterally spaced from the chaincenter outside of the engagement areas of the link assemblies; and adrive device, the drive device including at least two sprockets, withone sprocket engaging the link assemblies at a sprocket engagement areaon one side of the center of the chain and another sprocket engaging thelink assemblies at a sprocket engagement area on another side of thecenter of the chain.